India's army chief accused Pakistan on Monday of detailed planning of an attack along Kashmir's de facto border last week in which two soldiers were killed and said India reserved the right to retaliate.
The comments, which came as public anger mounts over the decapitation of one of the slain soldiers, appear certain to further inflame tensions between the nuclear-armed enemies.
Last week's fighting was the worst outbreak of violence in Kashmir, the Himalayan region both nations claim, since the two sides agreed a ceasefire nine years ago. India and Pakistan have fought three wars since independence in 1947, two of them over Kashmir.
Army chief General Bikram Singh was speaking just hours before local commanders were to meet at the border to identify ways of reducing tensions and avoiding further clashes.
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"The attack on January 8 was premeditated, a pre-planned activity. Such an operation requires planning, detailed reconnaissance," Singh told a news conference in New Delhi.
He said India reserved the right to retaliate against provocative acts on the border at a time and place of its choosing.
"I expect all my commanders at the Line of Control to be both aggressive and offensive in the face of provocation and fire," he said.
Both armies have lost two soldiers each in fighting along parts of the 740-km (460-mile) ceasefire line this month. One of the Indians was decapitated, New Delhi said, inflaming tempers in the country and prompting his family to start a hunger strike demanding that the severed head be brought back.
Pakistan has termed the Indian allegations as propaganda and blamed it for violations on the ceasefire line.
Islamabad accused Indian soldiers of entering its territory and killing a soldier on January 6. India said Pakistani soldiers intruded about 600 metres (yards) into its territory two days later and killed two Indian soldiers on patrol, the attack Singh was referring to.
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Pakistan said one of its soldiers was killed in further fighting on Thursday.
Singh said the beheading was a "gruesome act" and against the ethics of soldiering. He said a strong protest had been lodged with Pakistani authorities through diplomatic channels.
The family members of the slain soldier, Hemraj Singh, have launched a hunger strike demanding retribution and that his severed head be back brought back.
"Our demand is not something big. My brother's head should be brought back and the Pakistanis should be taught a lesson," said Jai Singh in their village in northern India.